Publications
In Press
Article
Journal of Acoustic Society of America
Transient signals such as plosives in speech or castanets in audio do not have a specific modulation or periodic structure in time domain. However, in the spectral domain they exhibit a prominent modulation structure, which is a direct consequence of their narrow time localization. Based on this observation, a spectral-domain AM-FM model for transients is proposed. The spectral AM-FM model is built starting from real spectral zero-crossings. The AM and FM correspond to the spectral envelope (SE) and group delay (GD), respectively. Taking into account the modulation structure and spectral continuity, a local polynomial regression technique is proposed to estimate the GD function from the real spectral-zeros. The SE is estimated based on the phase function computed from the estimated GD. Since the GD estimation is parametric, the degree of smoothness can be controlled directly. Simulation results based on synthetic transient signals generated using a beta density function are presented to analyze the noise-robustness of the SE-GD model. Three specific applications are considered: (i) SE-GD based modeling of castanet sounds; (ii) appropriateness of the model for transient compression; and (iii) determining glottal closure instants in speech using a short-time SE-GD model of the linear prediction residue
Article
Multimedia Systems
This paper presents a RESTful Web service platform for building mixed reality applications for both Web browsers and mobile clients. Having a common service backend makes creating applications fast, simple, and open to 3rd parties. The paper presents two mixed reality applications that have been built on the platform. It summarizes requirements for a mixed reality platform and defines a mixed reality domain model that the platform and applications share. In addition, it describes how the clients can use the REST interface to perform operations on user-generated content, as well as access real life commercial geo-content such as street view panoramas and building models.
Article
Pervasive Computing
Nokia Research Center’s Multimedia Technologies Laboratory in Santa Monica, CA is exploring how to design engaging, entertaining, and exciting novel experiences using interactive pervasive technologies. This exploration is exemplified by their creation of a socially-activated gaming experience built upon a custom platform of a multitude of interactive pervasive technologies. The results of a series of user tests of the game are discussed and techniques for overcoming challenges associated with the design of interactive applications for pervasive platforms are highlighted as potentially generalizable design insights
Article
Personal and Ubiquitous Computing
In this paper, we investigate the relation-
ship between automatically extracted behavioral char-
acteristics derived from rich smartphone data and self-
reported Big-Five personality traits (Extraversion, Agree-
ableness, Conscientiousness, Emotional Stability and
Openness to Experience). Our data stems from smart-
phones of 117 Nokia N95 smartphone users, collected
over a continuous period of 17 months in Switzerland.
From the analysis, we show that several aggregated fea-
tures obtained from smartphone usage data can be in-
dicators of the Big-Five traits. Next, we describe a ma-
chine learning method to detect the personality trait of
a user based on smartphone usage. Finally, we study the
bene ts of using gender-speci c models for this task.
Apart from a psychological viewpoint, this study facil-
itates further research on the automated classi cation
and usage of personality traits for personalizing services
on smartphones.
Conference
134th Convention, Audio Engineering Society
Detection of tonal components from magnitude spectrum is an important initial step in several speech and audio processing applications. In this paper we present an approach for detecting sinusoidal components from the magnitude spectrum using “goodness-of-fit” test. The key idea is to test the null-hypothesis that the region of spectrum under observation is drawn from the magnitude spectrum of an ideal windowedsinusoid. This hypothesis is tested with a chi-square “goodness-of-fit” test. The outcome of this hypothesis test is a decision about the presence of sinusoid in the observed region of magnitude spectrum. We have evaluated the performance of proposed approach using synthetically generated samples containing steady and modulated harmonics in clean and noisy conditions.
Article
Data Mining and Knowledge Discovery
<p>We study the extent to which social ties between people can be<br />
inferred in large social network, in particular via active user interactions. In<br />
most online social networks, relationships are lack of meaning labels (e.g.,<br />
“colleague” and “intimate friends”) due to various reasons. Understanding<br />
the formation of different types of social relationships can provide us insights<br />
into the micro-level dynamics of the social network. In this work, we precisely<br />
define the problem of inferring social ties and propose a Partially-Labeled<br />
Pairwise Factor Graph Model (PLP-FGM) for learning to infer the type of<br />
social relationships. The model formalizes the problem of inferring social ties<br />
into a flexible semi-supervised framework. We test the model on three different<br />
genres of data sets and demonstrate that it is possible to accurately infer<br />
85% of social relationships. We further study how to maximally leverage user<br />
interactions to help improve the learning accuracy. Two active learning based<br />
algorithms are proposed to actively select relationships to query users for their<br />
labels. Experimental results show that with only a few user corrections, the<br />
accuracy of inferring social ties can be significantly improved. Finally, to scale<br />
the model to handle real large networks, a distributed learning algorithm has<br />
been developed.</p>
Article
Nano Letters
<p>We report the first successful application of an ordered bicontinuous double-gyroid vanadium pentoxide network in an electrochromic supercapacitor. The freestanding vanadia network was fabricated by electrodeposition into a voided block copolymer template that had self-assembled into the double-gyroid morphology. The highly ordered structure with 11.0-nm-wide struts and a high specific surface to bulk volume ratio of 161.4 /µm is ideal for fast and efficient lithium ion intercalation/extraction and faradaic surface reactions, which are essential for high energy and high power density electrochemical energy storage devices. Supercapacitors made from such gyroid-structured vanadia electrodes exhibit a high specific capacitance of 155 F/g and show a strong electrochromic color change from green/gray to yellow, indicating the capacitor's charge condition. The nanostructuring approach, and utilizing an electrode material which has intrinsic electrochemical color-change properties, are concepts that can be readily extended to other electrochromic intercalation compounds.</p>
Article
Chinese Computer Federation journal
<p>Online social networks (online social network) provide people with a sharing of content, instant communication, expanding the social platform. With the popularity of smart mobile devices such as smart phones, and mobile data transmission technology, social networking is rapidly advancing to the mobile terminal from the PC side, there has been a large number of new applications for mobile terminals and services. The mobile social network (mobile social networking) has been widespread concern in industry and academia. So, in the end what is a mobile social network? Is it an extension of online social networking but on the mobile? How to provide a better experience to users through mobile social networking? In this paper, we propose the concept of instantaneous social networking (Ephemeral Social Networking), describing how to use the instantaneous social networks to provide users with a truly mobile social networking experience, and discuss some research issues and challenges.</p>
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In Proceedings
ACM Conference of Computer Supported Cooperative Work
ACM
Article
ACM Transactions of Intelligent Systems and Technology
In Proceedings
Proceedings of the ACM SIGCHI Conference on Human Factors in Computing Systems
ACM
Article
IEEE Transactions on Parallel and Distributed Systems
In Proceedings
ACM SIGCHI Conference on Human Factors in Computing Systems
ACM
2013
Conference
Proceedings of the SIGCHI Conference on Human Factors in Computing Systems - CHI '13
ACM Press
We present a comparative evaluation of two touch-based group-binding methods, a leader-driven method and a peer-based method, against a more conventional group-binding method based on scanning and passwords. The results indicate that the participants strongly preferred the touch-based methods in both pragmatic and hedonic qualities as well as in the overall attractiveness. While the leader-driven method allowed better control over the group and required only one participant to be able to form a group, the peer-based method helped to create a greater sense of community and scaled better for larger group sizes and distances. As the optimal group-binding method depends on the social situation and physical environment, the binding methods should be flexible, allowing the users to adapt them to different contexts of use. For determining the order of the devices, manual arrangement was preferred over defining the order by touching.
Article
Journal of New Music Research
This article describes the evaluation and comparison of five prototypes designed for the discovery of new music. The prototypes were compared against each other using various qualitative and quantitative metrics, and the results were then used to formulate a set of design criteria for future music discovery applications. Based on the results of a user study with 40 participants, visually interesting user interfaces and new interaction paradigms can inspire users to explore music collections and provide playful and fun ways to find new music. Without textual search functionality, such applications should rather complement than replace traditional music-listening applications.
Article
International Journal of Arts and Technology
Playfulness can be observed in all areas of human activity. It is an attitude of making activities more enjoyable. Designing for playfulness involves creating objects that elicit a playful approach and provide enjoyable experiences. In this paper, we introduce the design and evaluation of the PLEX Cards and its two related idea generation techniques. The cards were created to communicate the 22 categories of a playful experiences framework to designers and other stakeholders who wish to design for playfulness. We have evaluated the helpfulness of both the cards and their associated techniques in two studies. The results show that the PLEX Cards and its associated techniques are valuable sources of inspiration when designing for playfulness.
Article
IEEE Communications Magazine
Operator controlled IP traffic offloading in cellular networks has been a lively topic in both product and standard development during recent years. Specifically, 3GPP has developed multiple IP traffic offloading solutions for their system architecture, typically requiring 3GPP-specific modifications for user equipment. We argue that an adequate lightweight access technology agnostic IP traffic offloading system is achievable with a generic internet layer solution. Such a solution can still utilize 3GPP system properties for operators to push offloading policies securely into mobile devices. We discuss existing 3GPP-specified offloading solutions and present three variations of our internet layer traffic offloading implementations, and compare them against 3GPP-specified solutions. Our hands-on experience in operator networks shows that such a direction is feasible and promising.
In Proceedings
CHI'13
ACM
MARSUI is a hardware deformable prototype exhibiting plastic (shape-retaining) behavior. It can track the shape that the user creates when deforming it. We envision that a set of predefined shapes could be mapped onto particular applications and functions. In its current implementation, we present three shapes that MARSUI can be deformed into: circular band, flat surface and sharp bent. These shapes map respectively onto the following applications: wristwatch, mobile phone and media player. Since the malleable interface can also take other forms, feedback plays an important role in guiding the user towards the predefined shapes. In this paper, we focus on investigating the possibilities that auditory feedback could offer in guiding the user towards reaching the intended shapes.
Conference
CHI '13 Extended Abstracts on Human Factors in Computing Systems - CHI EA '13
ACM Press
In this paper, we explore the interaction design space for interactive glasses. We discuss general issues with interactive glasses (i.e., optics, technology, social, form factors), and then concentrate on the topic of the nature of interaction with glasses and its implications to provide a delightful user experience with the NotifEye.
Article
IEEE Communications Magazine, Special Issue on Heterogeneous and Small Cell Networks (HetSNets)
In this paper, energy efficient methods for inter-frequency small cell discovery in heterogeneous networks is discussed under the framework of LTE-Advanced.
Conference
IEEE Radio and Wireless Week
In radio frequency (RF) power amplifiers (PA), power efficiency, linearity and cost are contradictory requirements. In the Long Term Evolution (LTE) and LTE-Advanced (LTE-A) standards by the Third Generation Partnership Project, maximum power reduction (MPR) is used to relax RF PA requirements in user equipment. In this paper, we analyze the gating factors that determine the MPR in multicluster transmission, a new feature in LTE-A that significantly changes the way unwanted emissions are distributed in the spectrum. The analysis can help in devising more advanced MPR formulas and in development of RF PA linearizers.
Conference
Wireless World Research Forum (WWRF)
Globally people increasingly depend on wireless communications and require significantly improved performance and services in the years to come. Traffic volumes are increasing exponentially, up to 1000-fold in the coming decade, at the same time the cost-per-bit and energy consumption should decrease. This results in increasing importance of dense small cell network and the need for new approaches for more efficient use of spectrum. New use cases and broadening of existing ones leads to a need to widen the range of supported features. These trends lead to efficient, scalable and versatile networks. All this needs to happen in a sustainable way, also contributing positively in other areas of life and business.
In this paper we address several technical challenges and solutions that are faced while realising these future systems.
In Proceedings
CHI'13
ACM
Display technology developments mean the next generation of visual output devices will extend beyond the rigid, flat surfaces with which we are familiar to those that the user or the machine can deform. These will allow users to physically push, pull, bend, fold or flex the display and facilitate a range of self-deformation to better represent on-screen content or support new modes of interaction. This workshop will provide a forum to examine, discuss and shape the three primary themes of research in this area: prototyping and implementation, interaction and experience design, and evaluation. It will bring together an interdisciplinary group of academic and industrial researchers to define the current and future challenges of crafting organic user experiences with deformable displays.
Book
NSN/Nokia Series
Wiley-Blackwell
Deploying IPv6 in 3GPP Networks – Evolving Mobile Broadband from 2G to LTE and Beyond. A practical guide enabling mobile operators to deploy IPv6 with confidence. The most widely used cellular mobile broadband network technology is based on the 3GPP standards. The history and background of the 3GPP technology is in the Global Mobile Service (GSM) technology and the work done in European Telecommunications Standards Institute (ETSI). This primary voice service network has evolved to be the dominant mobile Internet access technology. Deploying IPv6 in 3GPP Networks covers how Internet Protocol version 6 (IPv6) is currently defined in the industry standards for cellular mobile broadband, why and how this route was taken in the technology, and what is the current reality of the deployment. Furthermore, it offers the authors’ views on how some possible IPv6 related advances 3GPP networks may be improved during the coming years. It gives guidance how to implement and deploy IPv6 correctly in the Third Generation Partnership Project (3GPP) mobile broadband environment, and what issues one may face when doing so. The book covers 3GPP technologies from 2G to LTE, and offers some ideas for the future. Key features written by highly respected and experienced authors from the IPv6 / mobile world. Provides an explanation of the technical background for some not–so–obvious design choices, what to concentrate on, and what transition strategies should be used by the vendors and the operators Offers a useful reference guide for operators and vendors entering into IPv6 business.
In Proceedings
CHI'13
ACM
Deformable User Interfaces (DUIs) often require external confirmation of the status of the interface, which is normally provided visually. We propose that tactile cues can also be employed for this end. In a user study that presents both visual and tactile cues in redundancy, we found that both channels can be combined with no loss in user experience or performance. This validates our design for further research on multimodal designs that make use of no redundancy in the supporting cues.
Article
Pervasive and Mobile Computing
Context-aware computing is an exciting paradigm in which applications perceive and react to changing environments in an unattended manner. To enable behavioral adaptation, a context-aware application must dynamically acquire context data from different operating spaces in the real world, such as homes, shops and persons. Motivated by the sheer number and diversity of operating spaces, we propose a scalable context data management system in this paper to facilitate data acquisition from these spaces. In our system, we design a gateway framework for all operating spaces and develop matching algorithms to integrate the local context schemas of operating spaces into a global set of domain schemas upon which SQL-based context queries can be issued from applications. The system organizes the operating space gateways as peers in semantic overlay networks and employs distributed query processing techniques over these overlays. Evaluation results on a prototype implementation demonstrate the effectiveness of our system design.
Article
interactions
According to Cisco, in 2012 we reached the point where there were more mobile phones than people on Earth (there are now also more people with access to a mobile device than a toothbrush). What used to be a device mostly for professional use now pervades every aspect of our lives. Today's mobile devices allow us to stay in touch, document our lives, buy our groceries, find our way to our next appointment, and even read a good ole book. People often say they feel naked, or that they are missing something, when they leave their mobile phones at home or at the office. Moreover, we are getting our first mobile phones at an ever younger age. In Finland, where part of this work took place, children get their first mobile phone at age 7 (together with the keys to their family's home). As we can see from these examples, mobile phones have become our companions, witnesses to our lives. However, this has all come at a cost—a social cost, perhaps. Sherry Turkle discusses some of the antisocial consequences that mobile phone use has had among teenagers in the U.S., critiquing networked life, a life where we become inseparable from our smartphones, where our social lives are happening online, where devices become substitutes for connecting with each other face-to-face, and where we would rather text than talk. Indeed, we see some of these symptoms popping up in other places, too, such as Finland, Wales, and Chile. The truth is, we are spending an awful amount of time emailing, texting, facebooking, and tweeting in our Western world. Our relationships with one another are mediated through screens, as opposed to happening directly in parks, cafes, pubs, or living rooms. But there is hope. The very devices that have partly removed the human touch from interpersonal communications could be the key to reestablishing and enriching face-to-face physical interactions.
Article
IEEE Pervasive Computing
In Book
Molecular Beam Epitaxy: From research to mass production
Elsevier
Article
Nanoenergy
In Book
Sonic Interaction Design
MIT Press
Article
J.Mater.Chem.A.
2012
Article
ACM Transactions on Intelligent Systems and Technology (ACM-TIST)
With the prevalence of smart mobile devices with multiple sensors, the commercial application of intelligent
context-aware services becomes more and more attractive. However, limited by the battery capacity, the
energy efficiency of context-sensing is the bottleneck for the success of context-aware applications. Though
several previous studies for energy efficient context-sensing have been reported, none of them can be applied
to multiple types of high energy consuming sensors. Moreover, applying machine learning technologies to
energy efficient context-sensing is under-explored too. In this paper, we propose to leverage machine learn-
ing technologies for improving the energy efficiency of multiple high energy consuming context sensors by
trading-off the sensing accuracy. To be specific, we try to infer the status of high energy consuming sen-
sors according to the outputs of software based sensors and the physical sensors that are necessary to work
all the time for supporting the basic functions of mobile devices. If the inference indicates the high energy
consuming sensor is in a stable status, we avoid the unnecessary invocation and instead use the latest in-
voked value as the estimation. The experimental results on real data sets show that the energy efficiency of
GPS sensing and audio level sensing are significantly improved by the proposed approach while the sensing
accuracy is over 90%.
Conference
ICMI '12
ACM
While gesture taxonomies provide a classification of device-based gestures in terms of communicative intent, little work has addressed the usability differences in manually performing these gestures. In this primarily qualitative study, we investigate how two sets of iconic gestures that vary in familiarity, mimetic and alphabetic, are affected under varying failed recognition error rates (0-20%, 20-40%, 40-60%). Drawing on experiment logs, video observations, subjects' feedback, and a subjective workload assessment questionnaire, results revealed two main findings: a) mimetic gestures tend to evolve into diverse variations (within the activities they mimic) under high error rates, while alphabet gestures tend to become more rigid and structured and b) mimetic gestures were tolerated under recognition error rates of up to 40%, while alphabet gestures incur significant overall workload with up to only 20% error rates. Thus, while alphabet gestures are more robust to recognition errors in keeping their signature, mimetic gestures are more robust to recognition errors from a usability and user experience standpoint, and thus better suited for inclusion into mainstream device-based gesture interaction with mobile phones.
In Proceedings
European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML PKDD)
Springer Berlin Heidelberg
We study ways of automatically inferring the level of attention a user is paying to auditory content, with applications for example in automatic podcast highlighting and auto-pause, as well as in a selection mechanism in auditory interfaces. In particular, we demonstrate how the level of attention can be inferred in an unsupervised fashion, without requiring any labeled training data. The approach is based on measuring the (generalized) correlation or synchrony between the auditory content and physiological signals reflecting the state of the user. We hypothesize that the synchrony is higher when the user is paying attention to the content, and show empirically that the level of attention can indeed be inferred based on the correlation. In particular, we demonstrate that the novel method of time-varying Bayesian canonical correlation analysis gives unsupervised prediction accuracy comparable to having trained a supervised Gaussian process regression with labeled training data recorded from other users.
Article
Journal of Visual Communication and Image Representation
We propose a patch-based image compression framework inspired by the inpainting techniques. The repeated patterns in one image are exploited for compression in a non-parametric manner, i.e., directly sampling image patches and encoding the similarity between them. We show how this idea leads to an assisted inpainting method, and how the inpainting method can be integrated into a patch-based image compression framework in a rate-distortion (R-D) optimal fashion. Two specific techniques - assisted inpainting for decoding, and R-D optimization for encoding by mode selection or image analysis - are presented in this paper. Experimental results show that compared with standard H.264 intra coding, our system (1) achieves up to 0.85 dB gain when optimized for objective quality and (2) saves as much as 25% bit-rate at similar subjective quality levels.
Conference
Proceedings of the 14th international conference on Human-computer interaction with mobile devices and services - MobileHCI '12
ACM Press
We present a new type of actuatable display, called Tilt Displays, that provide visual feedback combined with multi-axis tilting and vertical actuation. Their ability to physically mutate provides users with an additional information channel that facilitates a range of new applications including collaboration and tangible entertainment while enhancing familiar applications such as terrain modelling by allowing 3D scenes to be rendered in a physical-3D manner. Through a mobile 3x3 custom built prototype, we examine the design space around Tilt Displays, categorise output modalities and conduct two user studies. The first, an exploratory study examines users' initial impressions of Tilt Displays and probes potential interactions and uses. The second takes a quantitative approach to understand interaction possibilities with such displays, resulting in the production of two user-defined gesture sets: one for manipulating the surface of the Tilt Display, the second for conducting everyday interactions.
Article
Applied Physics Letters
We have observed multimode transport and high ON/OFF ratio in silicon nanochain devices.
Silicon nanochains grown by thermal evaporation of SiO solid sources consisted of chains of
silicon nanocrystals ~10 nm in diameter, separated by SiO2 regions. The devices were fabricated
using electron beam lithography on SiO2 thermally grown on silicon substrate. These devices
exhibited high ON/OFF current ratio up to 104. The inverse subthreshold slope as small as
500 mV/decade was observed in these devices. Therefore, we believe silicon nanochains hold
great potential to be used in field effect transistors.
Conference
SID 2012
We have built a prototype see-through near-eye display based on transparent plastic light guide exit-pupil expanders. The most important display attributes were optically characterized. In addition, subjective experiences in non-transparent and transparent modes were measured. All the results were compared to earlier measurement data from commercial near-eye displays.
Conference
Proceedings of the 14th international conference on Human-computer interaction with mobile devices and services - MobileHCI '12
ACM Press
We explore shared collocated interactions with mobile phones and public displays in an indoor public place. We introduce MobiComics, an application that allows a group of collocated persons to flexibly create and edit comic strip panels using their mobile phones. The prototype supports ad hoc sharing of comic strip panels between people and onto two public displays by taking the spatial arrangement of people into account, measured with a radio tracking technology integrated in their mobile phones. MobiComics also includes game-like elements to foster social interaction between participants. Our evaluations show that people enjoyed creating panels collaboratively and sharing content using the proposed interaction techniques. The included game-like features positively influenced social interaction.
Proceedings
14th International Conference on Ubiquitous Computing (UbiComp)
We describe and evaluate two methods for device pose classification and walking speed estimation that generalize well to new users, compared to previous work. These machine learning based methods are designed for the general case of a person holding a mobile device in an unknown location and require only a single low-cost, low-power sensor: a triaxial accelerometer. We evaluate our methods in straight-path indoor walking experiments as well as in natural indoor walking settings. Experiments with 14 human participants to test user generalization show that our pose classifier correctly selects among four device poses with 94% accuracy com- pared to 82% for previous work, and our walking speed estimates are within 12-15% (straight/indoor walk) of ground truth compared to 17-22% for previous work. Implementation on a mobile phone demonstrates that both methods can run efficiently online.
In Proceedings
Advances in Computer Entertainment (ACE)
Springer
User-generated content plays a pivotal role in the current social me- dia. The main focus, however, has been on the explicitly generated user content such as photos, videos and status updates on different social networking sites. In this paper, we explore the potential of implicitly generated user content, based on users’ online consumption behaviors. It is technically feasible to rec- ord users’ consumption behaviors on mobile devices and share that with rele- vant people. Mobile devices with such capabilities could enrich social interac- tions around the consumed content, but it may also threaten users’ privacy. To understand the potentials of this design direction we created and evaluated a low-fidelity prototype intended for photo sharing within private groups. Our prototype incorporates two design concepts, namely, FingerPrint and Mood- Photos that leverage users’ consumption history and emotional responses. In this paper, we report user values and user acceptance of this prototype from three participatory design workshops.
Article
Advances in Human-Computer Interaction
Traditionally only speech communicates emotions via mobile phone. However, in daily communication the sense of touch mediates emotional information during conversation. The present aim was to study if tactile stimulation affects emotional ratings of speech when measured with scales of pleasantness, arousal, approachability, and dominance. In the Experiment 1 participants rated speech-only and speech-tactile stimuli. The tactile signal mimicked the amplitude changes of the speech. In the Experiment 2 the aim was to study whether the way the tactile signal was produced affected the ratings. The tactile signal either mimicked the amplitude changes of the speech sample in question, or the amplitude changes of another speech sample. Also, concurrent static vibration was included. The results showed that the speech-tactile stimuli were rated as more arousing and dominant than the speech-only stimuli. The speech-only stimuli were rated as more approachable than the speech-tactile stimuli, but only in the Experiment 1. Variations in tactile stimulation also affected the ratings. When the tactile stimulation was static vibration the speech-tactile stimuli were rated as more arousing than when the concurrent tactile stimulation was mimicking speech samples. The results suggest that tactile stimulation offers new ways of modulating and enriching the interpretation of speech.
Article
IEEE Transactions on Haptics
This study investigates how controllability of force is influenced by concurrent vibrotactile feedback that is generated proportionally to the applied force. Three different models to provide tactile feedback are introduced: amplitude- and frequency modulation and granular synthesis. Then, an experiment investigating the effect of the feedback models on force control is reported. The tactile feedback conditions were compared to each other and to a condition with no feedback in a force repetition and a force hold tasks. In the force repetition task, all the feedback conditions yielded significantly better accuracy compared to no feedback condition. In the force hold task, there was no difference in the accuracy between the conditions including the no feedback condition. The results suggest that dynamic vibrotactile feedback assists the force control in force repetition tasks.
Conference
10th IEEE International NEWCAS Conference
This paper presents a state-of-the-art of wireless transceivers providing Gbps data-rate. This study focuses on the power consumption of such systems and puts it into balance with respect to the data-rate through the energy efficiency and with respect to the communication distance through a new Figure-of-Merit. An analysis of this state-of-the-art is also proposed which gives a new perspective on Gbps wireless systems.
Conference
Proceedings of the Designing Interactive Systems Conference - DIS '12
ACM Press
This paper builds upon the earlier work of Gaver on design workbooks by taking another design method and making a case for using it in HCI and interaction design. In this paper I discuss design mood boards, which consist of a collection of visually stimulating images and related materials. I present the results of an empirical study of how experienced designers from different disciplines (i.e., fashion, textile and industrial design) use mood boards as part of their work. The results suggest that mood boards can play five main roles in the early stages of the design process: framing, aligning, paradoxing, abstracting, and directing. I also reflect on design practice by providing concrete examples of mood boards and the resulting prototypes for an interaction design project. These examples are used to ground the discussion on the five roles found in the study.
Conference
Proceedings of the 14th international conference on Human-computer interaction with mobile devices and services companion - MobileHCI '12
ACM Press
This demonstration accompanies a full paper accepted into MobileHCI '12 [1]. We demonstrate a new type of actuatable display, called a Tilt Display, that provides visual feedback combined with multi-axis tilting and vertical actuation. Its ability to physically mutate provides users with an additional information channel that facilitates a range of new applications including collaboration and tangible entertainment while enhancing familiar applications such as terrain modelling by allowing 3D scenes to be rendered in a physical-3D manner.
Conference
ETSI Reconfigurable Radio Systems Workshop
This article introduces a novel flexible mobile device reconfiguration classes (MDRCs) framework which is expected to be applicable to future generation mass market reconfigurable radio devices. This framework sets the scene for a vision of a smooth evolution of reconfigurability features in mobile devices (MDs), paving the way from current, mainly static implementation choices toward a fully flexible device platform environment. For this flexible MD framework, baseband interfaces and software architecture of Software Defined Radio (SDR) MD are introduced as they are currently discussed in ETSI reconfigurable radio systems standardization. Furthermore, this technical solution is positioned with respect to security requirements and the basic regulatory framework which is currently under revision in Europe. Indeed, the future revised Radio Equipment and Telecommunications Terminal Equipment Directive (R&TTE Directive) is expected to allow for such advanced reconfiguration, enabling users to acquire and install so-called RadioApps software components which may affect the compliance of a MD to the essential requirements of the Directive.
Article
IEEE Wireless Communications Magazine
This article introduces a novel flexible mobile device reconfiguration classes (MDRCs) frame- work which is expected to be applicable to future generation mass market radio devices. This framework sets the scene for a vision of a smooth evolution of reconfigurability features in mobile devices, paving the way from current, mainly static implementation choices toward a fully flex- ible device platform environment. For this flexi- ble mobile device framework, baseband interfaces are introduced as they are currently discussed in ETSI reconfigurable radio systems standardization. Furthermore, this technical solution is positioned with respect to security requirements and the basic regulatory frame- work which is currently under revision in Europe. Indeed, the future revised Radio Equipment and Telecommunications Terminal Equipment Directive is expected to allow for such advanced reconfiguration, enabling users to acquire and install so-called RadioApps software compo- nents which may affect the compliance of a mobile device to the essential requirements of the Directive.
Conference
21st International World Wide Web Conference
ACM Press
Third-party applications (apps) drive the attractiveness of web and mobile application platforms. Many of these platforms adopt a decentralized control strategy, relying on explicit user consent for granting permissions that the apps request. Users have to rely primarily on community ratings as the signals to identify the potentially harmful and inappropriate apps even though community ratings typically reflect opinions about perceived functionality or performance rather than about risks. With the arrival of HTML5 web apps, such user-consent permission systems will become more widespread. We study the effectiveness of user-consent permission systems through a large scale data collection of Facebook apps, Chrome extensions and Android apps. Our analysis confirms that the current forms of community ratings used in app markets today are not reliable indicators of privacy risks of an app. We find some evidence indicating attempts to mislead or entice users into granting permissions: free applications and applications with mature content request more permissions than is typical; 'look-alike' applications which have names similar to popular applications also request more permissions than is typical. We also find that across all three platforms popular applications request more permissions than average.
